Cover Picture

Vol. 25, No. 6, June, 2014

ISSN 0103-5053JBCSJournal of the Brazilian Chemical Society

The cover picture shows that after electrochemical oxidation a phenoxyl radical species is formed. The synthesis and evaluation of radical formation of other four iron complexes are also described. The main difference in the structure of the complexes is related with the diazocyclic units of the ligands: piperazine, homopiperazine, hexahydropyrimidine or hexahydropyrimidin-5-ol. Details are presented in the Article Iron Complexes Containing Electrochemically Active Diazocycle-bis(di-tert-butyl-phenol) Ligands by Luísa L. Mendes, Christiane Fernandes, Roberto W. Franco, Leonardo M. Lube, Sheng-Hsuan Wei, Joseph H. Reibenspies, Donald J. Darensbourg and Adolfo Horn Jr. on page 1050.

Contents

Articles987 Regioselective Preparation of Thiamphenicol Esters Through

Lipase-Catalyzed ProcessesMarcos R. da Silva, Tasso G. C. Montenegro, Marcos C. de Mattos, Maria da Conceição F. de Oliveira, Telma L. G. de Lemos, Gonzalo de Gonzalo, Iván Lavandera, Vicente Gotor-Fernández and Vicente Gotor

Graphical AbstractThe lipase-catalyzed synthesis of thiamphenicol derivatives has been studied through complementary acylation and hydrolytic approaches,

finding Candida antarctica lipase B as the most efficient biocatalyst for the selective modification of both thiamphenicol and thiamphenicol

diacetate, respectively

SI online

J. Braz. Chem. Soc.iv

995 Prenylated Flavonoids from Roots of Dahlstedtia glaziovii (Fabaceae)Edione F. Canzi, Francisco A. Marques, Sirlei D. Teixeira, Ana Maria G. A. Tozzi, Marcos J. Silva, Renata Maria T. Duarte, Marta Cristina T. Duarte, Ana Lúcia T. G. Ruiz, Paula A. Monteiro, João E. de Carvalho and Beatriz Helena L. N. Sales Maia

Graphical AbstractA phytochemical study of roots of Dahlstedtia glaziovii (Fabaceae)

furnished a new dibenzoylmethane glaziovione, along with eighteen known compounds. The antiproliferative activity of the isolated

dibenzoylmethanes and flavones were investigated, being the dibenzoylmethanes more active than flavones

1002 An Efficient Synthesis of Novel Bis-Chalcones and Bis-Pyrazolines in the Presence of Cellulose Sulfuric Acid as Biodegradable Catalyst under Solvent-Free ConditionsZeba N. Siddiqui and Tabassum Khan

Graphical AbstractNovel synthesis of bis-chalcones and bis-pyrazolines using cellulose

sulfuric acid as highly efficient and biodegradable heterogeneous catalyst under solvent-free conditions

1021 Theoretical Studies of the Insertion of Carbenes in the Zeolite Framework: Modification of the Acidity and Creation of Chiral SitesMaria Beatriz S. Mota, Nilton Rosenbach Jr. and Claudio J. A. Mota

Graphical AbstractCalculations show that insertion of carbenes into the framework

structure of zeolite Y is thermodynamically favored, affecting the acid strength and creating chiral sites in the structure

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1012 Synthesis, Antibacterial, Anthelmintic and Anti-Inflammatory Studies of Novel Methylpyrimidine Sulfonyl Piperazine DerivativesNadigar R. Mohan, Swamy Sreenivasa, Karikere E. Manojkumar, Tadimety M. C. Rao, Boreddy S. Thippeswamy and Parameshwar A. Suchetan

Graphical AbstractMethylpyrimidine sulfonyl piperazine 3d optimized structures.

Substituted sulfonyl piperazines with pyrimidine, piperazine and sulfonamide functionality, a combination of three pharmacologically

important moieties, was synthesized and their antibacterial, anthelmintic and anti-inflammatory activities were evaluated

vVol. 25, No. 6, 2014

1029 Pyranoflavylium Derivatives Extracted from Wine Grape as Photosensitizers in Solar CellsChristiane M. Santos, Bárbara Gomes, Luís M. Gonçalves, Joana Oliveira, Sandra Rocha, Manuel Coelho, José A. Rodrigues, Victor Freitas and Helena Aguilar

Graphical AbstractDyes obtained from grapes were used as sensitizers in dye-sensitized

solar cells with efficiencies up to 0.08%. Moreover, the direct use of Port wine drops curiously resulted in an efficiency of 0.025%

1036 Phytate Decreases Oxidative Damage Caused by Labile Forms of Iron in Solution, Blood Plasma and in HeLa CellsFrederico A. Schleh, Orlando Chiarelli-Neto, Mayara N. Fontes, Renato Najjar and Breno P. Espósito

Graphical AbstractPhytate is a natural product that was found to be antioxidant in models

of iron-overload disorders

1050 Iron Complexes Containing Electrochemically Active Diazocycle-bis(di-tert-butyl-phenol) LigandsLuísa L. Mendes, Christiane Fernandes, Roberto W. A. Franco, Leonardo M. Lube, Sheng-Hsuan Wei, Joseph H. Reibenspies, Donald J. Darensbourg and Adolfo Horn Jr.

Graphical AbstractFour mononuclear and one dinuclear iron(III) compounds were

synthesized employing four different ligands, which are distinct with respect to the diazocycle backbone. Electrochemical data showed that

the compounds show ligand-centered redox processes. The formation of phenoxyl radical was confirmed by EPR and UV-Vis spectroscopies for

complexes [FeL2Cl], [Fe2(L4)(HL4)Cl] and [FeL4]

SI online

1041 Amphiphilic Planar Membranes in Ionic Equilibrium: a Study of pH Position-Dependent ValuesGuilherme V. Bossa, Davi R. Ratero, Augusto A. Neto, Alfred Fahr and Tereza P. Souza

Graphical AbstractA membrane with ionizable groups is modeled as a plan with a negative

charge density. Results for dissociation degree and pH variation with the ionic strength are presented for the Poisson-Boltzmann equation (PB) and

its linear form (LPB)

J. Braz. Chem. Soc.vi

1062 Determination of Rare Earth Elements in Spent Catalyst Samples from Oil Refinery by Dynamic Reaction Cell Inductively Coupled Plasma Mass SpectrometryJessee S. A. Silva, Tatiane de A. Maranhão, Fernando J. S. de Oliveira, Adilson J. Curtius and Vera L. A. Frescura

Graphical AbstractFluid catalytic cracking (FCC) spent catalyst as a source of rare earth

elements (REE) - an interesting application in agreement with the recycling-recovery concept

1071 Using of a Graphite-Polyurethane Composite Electrode Modified with a Schiff Base as a Bio-Inspired Sensor in the Dopamine DeterminationSidney X. dos Santos and Éder T. G. Cavalheiro

Graphical AbstractResponse in different dopamine concentrations and analytical curve

1086 Thin Film-XRF Determination of Uranium Following Thin-Film Solid Phase Extraction Jalal Hassan, Seyed M. Hosseini, Shahla Mozaffari, Babak Jahanparast and Mohammad H. Karbasi

Graphical AbstractA sensitive method based on the preconcentration of uranium on modified filter paper (thin-film solid phase extraction) has been

developed to determinate this element in water and soil samples by X-ray fluorescence

SI online

1078 Preconcentration and Determination of Cadmium in Water and Food Samples by in situ Surfactant-Based Solid-Phase Extraction and Flame Atomic Absorption SpectrometryMohammad Reza Jamali and Afsaneh Boromandi

Graphical AbstractIn situ surfactant-based solid-phase extraction (ISS-SPE) is proposed as a preconcentration procedure for the determination of cadmium in water

and food samples by flame atomic absorption spectrometry. From left to right: sample solution; injection of NaPF6 solution; end of injection and

enlarged view of sedimented phase after centrifugation

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1091 ZnO Prepared by Solution Combustion Synthesis: Characterization and Application as PhotoanodeAdriana C. Lucilha, Renata Afonso, Paulo R. C. Silva, Luiz F. Lepre, Rômulo A. Ando and Luiz H. Dall’Antonia

Graphical AbstractZnO photoelectrodes produced by combustion synthesis process promote

the discoloration of methylene blue dye when irradiated with UV light

1101 International Comparisons for Coulometric Determinations of Dichromate Used to Develop Certified Reference Material for Oxidation-Reduction TitrationPaulo P. Borges and Wiler B. da Silva Junior

Graphical AbstractCharacterization process for certifying K2Cr2O7 as certified reference

material (CRM) by precise constant-current coulometry: from a candidate CRM until a certified value

1116 Vanadium-Binding Protein in Marine Plankton from Tropical South Atlantic OceanVinicius T. Kütter, Maria Montes-Bayón, Silvia M. Sella, Alfredo Sanz-Medel and Emmanoel V. Silva-Filho

Graphical AbstractCoupling of anionic exchange chromatography (AEC) with matrix-assisted

laser desorption-ionization-time of flight (MALDI-TOF) in order to determine the molecular mass of V-binding protein(s) in phytoplankton

(> 64 mm) from Cabo Frio

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1108 Analysis of Carotenoids, α-Tocopherol, Sterols and Phenolic Compounds from White Bread Enriched with Chia (Salvia hispanica L.) Seeds and Carrot (Daucus carota L.) LeavesSwami A. Maruyama, Thiago Claus, Lucas U. R. Chiavelli, Janksyn Bertozzi, Eduardo J. Pilau, Nilson E. de Souza, Jesuí V. Visentainer, Sandra T. M. Gomes and Makoto Matsushita

Graphical AbstractA Box-Behnken design and correlation studies were applied in order to

obtain more information about how specific antioxidants affect the total antioxidant activity and the degree of forced oxidation in white breads

with chia seeds and carrot leaves

J. Braz. Chem. Soc.viii

1124 Release of Vitamin B12 and Diclofenac Potassium from N,N-dimethylacrylamide-modified Arabic Gum Hydrogels - the Partition-Diffusion Model Ricardo Bossoni, André Riul, Artur J. M. Valente, Adley F. Rubira and Edvani C. Muniz

Graphical Abstract3D hydrogel matrices based on GAm (chemically modified Arabic Gum) and DAAm (dimethyl acrylamide) were prepared on GAm:DMAAm rate 60:40 w:w. Essays of solutes (VitB12 and DFK) release from 3D matrices

were performed. The partition-diffusion model allows predicting whole profile of release in any case. It was verified that α/kR ratio is not volume

dependent, at a certain temperature, but the temperature strongly influences such ratio for both solutes

Short Reports1135 1H HR-MAS NMR and S180 Cells: Metabolite Assignment

and Evaluation of Pulse SequenceAline L. de Oliveira, Bruno César B. Martinelli, Luciano M. Lião, Flávia C. Pereira, Elisangela P. Silveira-Lacerda and Glaucia B. Alcantara

Graphical AbstractS180 cells, a model of tumor murine for testing drug candidates

with potential anticancer activity, were studied by HR-MAS NMR for establishing optimal pulse sequence and metabolite assignment

1143 Ischemic Stroke Progress Evaluation by 31P NMR-Based Metabonomic of Human SerumCaroline W. P. S. Grandizoli, Marcos C. Lange, Felipe T. M. Novak, Francinete R. Campos and Andersson Barison

Graphical AbstractIn this work, 31P NMR-based metabonomic of human blood serum allowed

to discriminate ischemic stroke patients from health individuals and gives insights over the mechanism triggered by ischemic stroke